Accommodating intraocular lenses and methods of use

ABSTRACT

Fluid-driven accommodating intraocular lenses comprising deformable optic portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of pending U.S. application Ser. No.12/782,644, filed May 18, 2010; which is a continuation of U.S.application Ser. No. 10/358,038, filed Feb. 3, 2003, now U.S. Pat. No.8,048,155, which claims benefit under 35 U.S.C. §119(e) of ProvisionalPatent Application No. 60/353,847 filed Feb. 2, 2002 titled “IntraocularLens and Method of Making”; and also claims benefit of the followingother Provisional Patent Applications: No. 60/362,303 filed Mar. 6, 2002titled “Intraocular Lens and Method of Making”; No. 60/378,600 filed May7, 2002 titled “Intraocular Devices and Methods of Making”; No.60/405,471 filed Aug. 23, 2002 titled “Intraocular Implant Devices andMethods of Making”, No. 60/408,019 filed Sep. 3, 2002 titled“Intraocular Lens”, and No. 60/431,110 filed Dec. 4, 2002 titled“Intraocular Implant Devices and Methods of Making”. All of the aboveapplications are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to intraocular implant devices andmore specifically to shape memory capsular shaping devices for combiningwith a post-phacoemulsification capsular sac to provide a biomimeticcomplex that can mimic the energy-absorbing and energy-releasingcharacteristics of a natural young accommodative lens capsule. The shapememory capsular shaping devices can further be combined with anindependent or integrated optics to provide an accommodating intraocularlens.

2. Description of the Related Art

The human lens capsule can be afflicted with several disorders thatdegrade its functioning in the vision system. The most common lensdisorder is a cataract which consists of the opacification of thenormally clear, natural crystalline lens matrix in a human eye. Theopacification usually results from the aging process but can also becaused by heredity or diabetes. FIG. 1A illustrates a lens capsulecomprising a capsular sac with an opacified crystalline lens nucleus. Ina typical cataract procedure as performed today, the patient's opaquecrystalline lens is replaced with a clear lens implant or IOL. (SeeFIGS. 1A and 1B.) The vast majority of cataract patients must wearprescription eyeglasses following surgery to see properly. The IOLs inuse today provide the eye with a fixed focal length, wherein focusing onboth close-up objects and distant objects is not possible. Intraocularlens implantation for cataracts is the most commonly performed surgicalprocedure in elderly patients in the U.S. Nearly three million cataractsurgeries are performed each year in the U.S., with an additional 2.5million surgeries in Europe and Asia.

Mechanisms of Accommodation. Referring to FIG. 1A, the human eye definesan anterior chamber 10 between the cornea 12 and iris 14 and a posteriorchamber 20 between the iris and the lens capsule 102. The vitreouschamber 30 lies behind the lens capsule. The lens capsule 102 thatcontains the crystalline lens matrix LM or nucleus has an equator thatis attached to cobweb-like zonular ligaments ZL that extend generallyradially outward to the ciliary muscle attachments. The lens capsule 102has transparent flexible anterior and posterior walls or capsularmembranes that contain the crystalline lens matrix LM.

Accommodation occurs when the ciliary muscle CM contracts to therebyrelease the resting zonular tension on the equatorial region of the lenscapsule 102. The release of zonular tension allows the inherentelasticity of the lens capsule to alter it to a more globular orspherical shape, with increased surface curvatures of both the anteriorand posterior lenticular surfaces. The lens capsule together with thecrystalline lens matrix and its internal pressure provides the lens witha resilient shape that is more spherical in an untensioned state.Ultrasound biomicroscopic (UBM) images also show that the apex of theciliary muscle moves anteriorly and inward—at the same time that theequatorial edge the lens capsule moves inwardly from the sclera duringaccommodation.

When the ciliary muscle is relaxed, the muscle in combination with theelasticity of the choroid and posterior zonular fibers moves the ciliarymuscle into the unaccommodated configuration, which is posterior andradially outward from the accommodated configuration. The radial outwardmovement of the ciliary muscles creates zonular tension on the lenscapsule to stretch the equatorial region of lens toward the sclera. Thedisaccommodation mechanism flattens the lens and reduces the lenscurvature (both anterior and posterior). Such natural accommodativecapability thus involves contraction and relaxation of the ciliarymuscles by the brain to alter the shape of the lens to the appropriaterefractive parameters for focusing the light rays entering the eye onthe retina—to provide both near vision and distant vision.

In conventional cataract surgery as depicted in FIGS. 1B and 1C, thecrystalline lens matrix is removed leaving intact only the thin walls ofthe anterior and posterior capsules—together with zonular ligamentconnections to the ciliary muscles. The crystalline lens core is removedby phacoemulsification through a curvilinear capsularrhexis asillustrated in FIG. 1B, i.e., the removal of an anterior portion of thecapsular sac. FIG. 1B then depicts a conventional 3-piece IOL just afterimplantation in the capsular sac.

FIG. 1C next illustrates the capsular sac and the prior art 3-piece IOLafter a healing period of a few days to weeks. It can be seen that thecapsular sac effectively shrink-wraps around the IOL due to thecapsularrhexis, the collapse of the walls of the sac and subsequentfibrosis. As can be easily understood from FIGS. 1B and 1C, cataractsurgery as practiced today causes the irretrievable loss of most of theeye's natural structures that provide accommodation. The crystallinelens matrix is completely lost—and the integrity of the capsular sac isreduced by the capsularrhexis. The shrink-wrap of the capsular sacaround the IOL damages the zonule complex, and thereafter it is believedthat the ciliary muscles will atrophy.

Prior Art Pseudo-Accommodative Lens Devices. At least one commerciallyavailable IOL, and others in clinical trials, are claimed to“accommodate” even though the capsular sac shrink-wraps around the IOLas shown in FIG. 1C. If any such prior art lens provide variablefocusing power, it is better described as pseudo-accommodation since allthe eye's natural accommodation mechanisms of changing the shape of thelens capsule are not functioning. Perhaps the most widely known of thepseudo-accommodative IOLs is a design patented by Cumming which isdescribed in patent disclosures as having hinged haptics that areclaimed to flex even after the capsular sac is shrink-wrapped around thehaptics. Cumming's patents (e.g., U.S. Pat. Nos. 5,496,366; 5,674,282;6,197,059; 6,322,589; 6,342,073; 6,387,126) describe the hinged hapticsas allowing the lens element to be translated forward and backward inresponse to ciliary muscle contraction and relaxation within theshrink-wrapped capsule. The Cumming IOL design is being commercializedby C&C Vision, 6 Journey, Ste. 270, Aliso Viejo, Calif. 92656 as theCrystaLens AT-45. However, the medical monitor for the CrystaLens AT-45in Phase I FDA trials explained in an American Society of Cataract andRefractive Surgeons (ASCRS) presentation, when asked about movement ofAT-45's hinged haptics, that the AT-45 was not “moving much” at theoptic and hinge. It is accepted that the movement of such a lens isentirely pseudoaccommodative and depends on vitreous displacement thatpushes the entire IOL slightly anteriorly (see:http://www.candcvision.com/ASCRSCCTa-lks/Slade/Slade.htm). A similar IOLthat is implanted in a shrink-wrapped capsule and in sold in Europe byHumanOptics, Spardorfer Strasse 150, 90154 Erlangen, Germany. TheHumanOptics lens is the Akkommodative 1CU which is not available in theU.S., due to lack of FDA approval. In sum, any prior art IOLs that areimplanted in an enucleated, shrink-wrapped lens capsule probably are notflexed by ciliary muscle relaxation, and exhibit only apseudo-accommodative response due to vitreous displacement.

Since surgeons began using IOLs widely in the 1970's, IOL design andsurgical techniques for IOL implantation have undergone a continuousevolution. While less invasive techniques for IOL implantation and newIOL materials technologies have evolved rapidly in the several years,there has been no real development of technologies for combining thecapsular sac with biocompatible materials to provide a biomimeticcapsular complex. What has stalled all innovations in designing a trulyresilient (variable-focus) post-phaco lens capsule has been is the lackof sophisticated materials.

What has been needed are materials and intraocular devices that beintroduced into an enucleated lens capsule with a 1 mm. to 2.5 mm.injector, wherein the deployed device and material provide the exactstrain-absorbing properties and strain-releasing properties needed tocooperate with natural zonular tensioning forces. Such an intraoculardevice will allow for the design of dynamic IOLs that can replicatenatural accommodation. Microdevices of intelligent elastic compositematerials can provide the enabling technology to develop new classes ofaccommodating IOL systems.

SUMMARY OF THE INVENTION

This invention relates to novel shape memory devices, materials andcapsular shaping elements (CSEs) that can be implanted usingconventional techniques to create a biomimetic lens capsule complex. Thecapsular shaping element, or more specifically an intracapsular implant,is designed to provide the implant/lens capsule complex with a shape andresiliency that mimics the elasticity of a young, still-accommodativelens capsule. In one embodiment, the capsular shaping elementincorporates at least one thin-film expanse of a shape memory alloy(SMA) material in a three dimensional shape to impart the requiredelasticity to the CSE. The capsular shaping element will enable, and canbe integrated with, several classes of optic elements to provide anaccommodative IOL system that cooperates with ciliary muscle tensioningand de-tensioning to provide variable focusing power. The accommodatingIOL corresponding to the invention can be used following typicalcataract surgeries, or can be used in refractive lensectomy proceduresto treat presbyopia.

In a preferred embodiment, the capsular shaping element incorporates aleast one formed expanse of thin-film nickel titanium alloy (NiTi orNitinol). Nitinol materials have the unique capability to absorb energyby a reversible crystalline transformation (superelasticity) which isorders of magnitude higher than can be absorbed in plastic deformationsof conventional resilient materials, such as a polymers used in otherso-called accommodating IOL designs. In addition, such NiTi materialshave the ability to avoid localization of plastic deformations—and thuscan spread the absorbed energy over a much larger region of thematerial. Further, a capsular shaping element that relies on NiTi forits shape memory characteristics need only be microns in thickness forcompacted introduction into the lens capsule. The implant, in fact, maybe little thicker than the lens capsule itself. Nickel titanium alloysare also known to be biocompatible. In preferred variants of biomimeticCSEs described herein, the implant carries at least one seamless expanseof thin-film NiTi material that three dimensionally formed to engage theanterior and posterior capsules—while leaving an open central opticzone. Various types of optic elements can be coupled to the capsularshaping element of the invention.

In such preferred embodiments, the capsular shaping body also comprisesin part a shape memory polymer (SMP) component that encases the shapememory alloy form, whether of a thin film SMA or another formedstructure of a nickel titanium alloy. The shape memory polymer iscapable of a memory shape as well as a compacted temporary shape. In itstemporary compacted shape, the polymer together with the embeddedsuperelastic nickel titanium can be ultrathin and three dimensionallystable to be rollable for use in standard diameter injector or even asub-1 mm. injector.

In another preferred embodiment, the non-optic or peripheral bodyportion of the implant is again of a shape memory polymer, and optionalSMA form, that engages the enucleated lens capsule to provide apost-phaco biomimetic complex that mimics the energy-absorbing andenergy-releasing characteristics of an accommodative lens capsule. Anadaptive lens element is coupled to the annular peripheral body portion.In this embodiment, the peripheral capsular shaping portion of theimplant body carries at least one fluid-filled interior chamber thatcommunicates with a central chamber in the adaptive lens element thatactuates a deformable surface thereof. The flexing of the peripheralbody portion in response to zonular tensioning and de-tensioningprovides an adaptive optic mechanism wherein fluid media flows betweenthe respective chambers to deform the lens surface to increase ordecrease lens power. For example, in one embodiment, the peripheral bodyportion carries a posterior negative power lens that can be altered inpower during accommodation to cooperate with a second lens element toprovide variable focus.

Accordingly, a principal advantage of the present invention is theprovision of deformable, rollable intraocular devices such as capsularshaping devices that utilize shape memory alloy forms, such shapingdevices enabling an artificial lens system to provide accommodativeamplitude (diopters of power modification).

The invention advantageously provides a capsular shaping element withintegrated optics that require only a very small entry incision forimplantation—for example a sub-1 mm. minimal incision through thecornea.

The invention advantageously provides an independent module comprising acapsular shaping structure of a thin film material that conforms to andmaintains an intracapsular volume for receiving an IOL.

The invention provides a capsular shaping structure of a superelasticshape memory alloy form within a shape memory polymer envelope thatconforms to and maintains an intracapsular volume.

The invention advantageously provides an independent module comprising acapsular shaping structure that can cooperate with drop-in fixed focusIOL or a drop-in accommodating IOL.

The invention advantageously provides an independent module comprising acapsular shaping element that allows for simplified lens exchange.

The invention provides an independent module comprising a capsularshaping structure that is adapted to cooperate with, and amplify,zonular tensioning and de-tensioning caused by ciliary muscle relaxationand contraction to enable various types of accommodating lens systems.

The invention advantageously provides a modular capsular shaping elementthat is adapted to cooperate with both (i) vitreous displacement causedby ciliary muscle contraction; and (ii) zonular tensioning andde-tensioning caused by ciliary muscle relaxation and contraction, toamplify lens translation in novel types of accommodating lens systems.

The invention provides an IOL with optic or non-optic body portions thatcarry a photomodifiable SMP that can be irradiated to adjust anoperational parameter of an adaptive optic or accommodating lens system.

The invention provides an IOL with a polymer non-optic body portion thatcarries an anti-fibrotic pharmacological agent for release about thecapsular sac for preventing or limiting fibrosis and shrinkage of thecapsular sac.

These and other objects of the present invention will become readilyapparent upon further review of the following drawings andspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention and to see how it may becarried out in practice, some preferred embodiments are next described,by way of non-limiting examples only, with reference to the accompanyingdrawings, in which like reference characters denote correspondingfeatures consistently throughout similar embodiments in the attacheddrawings.

FIG. 1A is a perspective cut-away view of an eye with an opacified lenscapsule.

FIG. 1B is a perspective cut-away view of the eye of FIG. 1A with acurvilinear capsularrhexis and the crystalline lens matrix removed byphacoemulsification, together with the implantation of a prior art3-piece IOL.

FIG. 1C is a perspective cut-away view of the eye of FIG. 1B showing thelens capsule after wound healing wherein the lens capsule shrink-wrapsaround the prior art IOL.

FIG. 2 is a stress-strain graph of the thin-film superelastic nickeltitanium alloy that is utilized in a preferred embodiment of theinvention.

FIG. 3A is a schematic depiction of the crystalline lattice of thethin-film superelastic nickel titanium alloy of FIG. 2 in a martensitestate.

FIG. 3B is a depiction of the crystalline lattice of the superelasticnickel titanium alloy of FIG. 3A in its memory austhenite state.

FIG. 4 is a perspective cut-away view of a lens capsule and Type “A”intraocular device corresponding to the invention comprising adeformable, rollable ultrathin capsular shaping element (CSE) of athin-film expanse of shape memory material encased in a polymer.

FIG. 5 is a perspective cut-away view of the lens capsule of FIG. 4 thatillustrates anterior and posterior engagement planes of the capsule thattargeted for engagement by the Type “A” capsular shaping element (CSE)of FIG. 4.

FIG. 6 is a cut-away view of an alternative Type “A” capsular shapingelement similar to that of FIG. 4 with a posterior annular body portionof a polymer.

FIG. 7 is a cut-away partial view of another alternative Type “A”capsular shaping element similar to that of FIGS. 4 and 6; thisembodiment configured to provide additional stress-absorbing featuresand a non-elliptical equatorial region for allowing slight shrinkage ofthe lens capsule.

FIG. 8A is a schematic sectional view of a post-phaco lens capsule withits equatorial envelope after being shaped by the implant of FIG. 4 orFIG. 6.

FIG. 8B is a schematic sectional view of a post-phaco lens capsule withits equatorial envelope after being shaped by the implant of FIG. 7wherein the equatorial region is non-elliptical after capsule shrinkageto reduce laxity in the zonular ligaments.

FIG. 9 is a cut-away view of an alternative Type “A” capsular shapingimplant that comprises an elastic composite structure for creatingenhanced stress-bearing capacity.

FIG. 10 is a cut-away view of an alternative Type “A” capsular shapingelement that carries a biodegradable SMP or shape memory polymer forautomatically altering the stress-bearing capacity of the implantfollowing the wound healing response.

FIG. 11 is a cut-away view of another Type “A” capsular shaping elementthat carries an adjustable shape memory polymer (SMP) that responds tostimulus from a remote source for altering the stress-bearing capacityof the implant in the post-implant period.

FIG. 12 is a cut-away view of Type “A” composite capsular shaping bodyof a thin-film shape memory alloy and an outer polymer envelope.

FIGS. 13A-13B are sectional schematics of a Type “B” capsular shapingelement with integrated optic element showing disaccommodative andaccommodative positions, respectively.

FIG. 14 is a cut-away view of the Type “B” IOL of FIGS. 13A-13B.

FIGS. 15A-15B are sectional schematics of another Type “B” capsularshaping element with integrated fluid-filled adaptive optic element.

FIG. 15C is a view of another Type “B” capsular shaping body with andintegrated gel-filled optic element that substantially occupies thevolume of the capsular sac.

FIG. 16A is a sectional view of another Type “B” capsular shapingelement with a posterior negative power adaptive lens element with fluiddisplacement means for altering the lens power.

FIG. 16B is a perspective view of the implant device of FIG. 16A.

FIG. 17 is a view of a Type “B” intraocular device of FIG. 16A showing amethod of rolling the device for introduction into the eye, the body ofa shape memory polymer (SMP) encasing a shape memory alloy form.

FIG. 18 is an exploded view of the two components of the device of FIG.16A, showing flow channels between the interior chambers of theperipheral non-optic portion and the optic portion.

FIG. 19 is a sectional view of an alternative intraocular device similarto FIG. 16A showing a drop-in IOL in phantom view engaged with theimplant device of FIG. 16A.

FIG. 20A is a sectional view of the intracapsular device of FIG. 16A at,or urged toward, its memory shape as when implanted in a capsular sac.

FIG. 20B is a sectional view of the intracapsular device of FIG. 20Adeformed toward a temporary shape showing a flow of fluid from theperipheral non-optic portion to the optic portion to alter the power ofthe lens.

FIG. 21 is a sectional view of a capsular shaping body and adaptivebi-convex optic with communicating peripheral and central chamberportions showing accommodative and disaccommodative shapes.

FIG. 22 is a cut-away view of an alternative intraocular device similarto FIG. 16A illustrating a plurality of regions of a shape memorypolymer adjacent to an interior space that are responsive to an externalenergy source to alter fluid flows and the dynamics of fluiddisplacement in the optic portion.

FIG. 23 is a perspective illustration of a capsular shaping system thatutilizes first and second cooperating independent devices (in anaccommodative shape), each similar to the device of FIG. 16A, one devicefor engaging the posterior capsule and a limited equatorial capsularregion and the second device adapted for engaging only the anteriorcapsule and a limited equatorial region.

FIG. 24 is a perspective view of capsular shaping system of FIG. 23 withthe cooperating independent devices in a disaccommodative shape.

FIG. 25 is a sectional view of an alternative intracapsular implant andadaptive optic with a shape memory polymer peripheral body that carriesand interior fluid-filled chamber.

FIG. 26 is a sectional view of an alternative intracapsular implant andadaptive optic similar to that of FIG. 25 with alternative interiorchamber locations.

FIG. 27 is a sectional view of an alternative intracapsular implant andadaptive optic similar to that of FIG. 26.

FIG. 28 is a sectional view of an alternative intracapsular implant withfirst and second adaptive optic elements that is similar to that of FIG.25.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Principles of Superelasticity and Shape Memory in Classes of OphthalmicImplant Materials

The capsular shaping element (CSE) of the invention is adapted forproviding a biomimetic lens capsule complex that will enable anaccommodative lens system, which can have several variants. The termbiomimetic lens capsule is derived from the word biomimesis, whichdefines the development of structures that mimic life, or that imitatebiological systems. In this case, the objective is to develop an implantthat mimics the inherent elasticity of a young lens capsule forcooperating with the ciliary muscle to alter the shape or translation ofan implanted optic element.

The biomimetic lens capsules corresponding to the invention are enabledby the phenomena of shape memory and superelasticity that are unique tocertain newly developed so-called intelligent materials. In particular,one embodiment of CSE comprises a thin-film expanse of a nickel titaniumalloy that is fabricated in a vacuum chamber deposition process. Thenickel titanium form is embedded within a thin biocompatible polymerenvelope. In the prior art, the principal uses of nickel titanium alloyshave been developed from uniaxial models of superelasticity, such as inwires and other bulk materials. The invention extends the use of nickeltitanium fabricated in thin film expanses. Additional embodimentscomprise, at least in part, an expanse of a shape memory polymer (SMP),a shape memory polymer foam, or a bioerodible shape memory polymer.

In order to understand the invention, it is useful to describe thephenomena of shape memory and superelasticity that are unique to nickeltitanium alloys, which are utilized in preferred embodiments of thecapsular shaping structures of the invention. In an unstressed state,the nickel titanium alloy component will present itself in an austhenitephase—in which phase it exhibits linear elasticity. When stress isapplied to the material, the austhenite phase transforms into amartensite phase that also exhibits linear elasticity, however, eachphase has a different constant as can be seen in FIG. 2. Theausthenite-martensite transformation produces a substantial level ofstrain (σ) that is developed over a relatively small range of stress(ε). Upon unloading the stress, the transformation is reversible;however, the stress levels at which the reversible transformation occursare smaller than the stresses that were require to produce the originalausthenite-martensite transformation, as depicted in FIG. 2. Since, uponunloading, the material completely recovers it original shape, it isdescribed as having elastic properties. In nickel titanium alloys, sincethe transformation strains are so large (greater that 6%) when comparedto other alloys (typically on the order 0.1%), the material is definedas superelastic.

The superelastic properties of NiTi, and its strain-induced martensitetransformation, can be understood by schematic illustrations of itscrystalline lattice structure. The austhentite and martensite phaseseach define a very distinct crystalline structure or phases, as depictedin FIGS. 3A and 3B. Which phase is present depends on temperature andthe amount of stress (consider it as internal pressure) being applied tothe material. If a thin-film expanse of nickel titanium alloy is cooledfrom above its transformation temperature, it will remain 100% austeniteuntil it reaches the martensite start temperature M_(s) for anyparticular amount of stress then being applied to the material. Asdepicted in FIG. 3A the sides of the martensite crystalline latticemarked a, b, and c are all different lengths. When pressure or stress(s) is applied to the lattice, these sides will change in length tocompensate for the deformation forces. The angle marked .beta. also canchange in response to such deforming forces. When the nickel titanium iselevated in temperature from below its crystallographic phase transitionas shown in FIG. 3B, the material will recover its precise “memory”shape above its austenite start (A_(s)) temperature which can bedesigned to be slightly below body temperature (37° C.). In itsaustenite phase, the nickel titanium has only one possible crystallineorientation, which will be a predetermined shape of the capsular shapingdevice. It is because of the wide variability of these latticeparameters that thin-film nickel titanium material can be easilydeformed in its martensite phase. This accounts for the “rubbery”superelastic nature of NiTi that allows 6% or more recoverable elasticdeformations.

The thin-film NiTi expanse of the invention can be fabricated asdescribed in U.S. Pat. No. 5,061,914 to D. Busch and A. D. Johnson andthe following published U.S. patent applications to A. D. Johnson etal.: No. 20020046783 A1 published Apr. 25, 2002; and No. 20010039449 A1published Nov. 8, 2001. All of the patents and applications referred toin this paragraph are incorporated herein in their entirely by thisreference.

The capsular shaping portion of the intracapsular implant correspondingto the invention also can be made in part, or in its entirety, from aclass of shape memory polymer (SMP). The term “shape memory” is used ina different context when referring to SMPs. A shape memory polymer issaid to demonstrate shape memory phenomena when it has a fixed temporaryshape that can revert to a memory shape upon a selected stimulus, suchas temperature. A shape memory polymer generally is characterized asdefining phases that result from glass transition temperatures insegregated linear block co-polymers: a hard segment and a soft segment.The hard segment of SMP typically is crystalline with a defined meltingpoint, and the soft segment is typically amorphous, with another definedtransition temperature. In some embodiments, these characteristics maybe reversed together with glass transition temperatures and meltingpoints.

In one embodiment, when the SMP material is elevated in temperatureabove the melting point or glass transition temperature of the hardsegment, the material then can be formed into a memory shape. Theselected shape is memorized by cooling the SMP below the melting pointor glass transition temperature of the hard segment. When the shaped SMPis cooled below the melting point or glass transition temperature of thesoft segment while the shape is deformed, that (temporary) shape isfixed. The original shape is recovered by heating the material above themelting point or glass transition temperature of the soft segment butbelow the melting point or glass transition temperature of the hardsegment. (Other methods for setting temporary and memory shapes areknown which are described in the literature below). The recovery of thememory original shape is thus induced by an increase in temperature, andis termed the thermal shape memory effect of the polymer. Thetemperature can be at or below body temperature (37° C.) or a selectedhigher temperature.

Besides utilizing the thermal shape memory effect of the polymer, thememorized physical properties of the SMP can be controlled by its changein temperature or stress, particularly in ranges of the melting point orglass transition temperature of the soft segment of the polymer, e.g.,the elastic modulus, hardness, flexibility, permeability and index ofrefraction. The scope of the invention of using SMPs in capsular shapingelements extends to the control of such physical properties,particularly in elastic composite structure described further below.

Examples of polymers that have been utilized in hard and soft segmentsof SMPs include polyurethanes, polynorborenes, styrene-butadieneco-polymers, cross-linked polyethylenes, cross-linked polycyclooctenes,polyethers, polyacrylates, polyamides, polysiloxanes, polyether amides,polyether esters, and urethane-butadiene co-polymers and othersidentified in the following patents and publications: U.S. Pat. No.5,145,935 to Hayashi; U.S. Pat. No. 5,506,300 to Ward et al.; U.S. Pat.No. 5,665,822 to Bitler et al.; and U.S. Pat. No. 6,388,043 to Langer etal. (all of which are incorporated herein by reference); Mather, StrainRecovery in POSS Hybrid Thermoplastics, Polymer 2000, 41(1), 528; Matheret al., Shape Memory and Nanostructure in Poly(Norbonyl-POSS)Copolymers, Polym. Int. 49, 453-57 (2000); Lui et al., ThermomechanicalCharacterization of a Tailored Series of Shape Memory Polymers, J. App.Med. Plastics, Fall 2002; Gorden, Applications of Shape MemoryPolyurethanes, Proceedings of the First International Conference onShape Memory and Superelastic Technologies, SMST InternationalCommittee, pp. 115-19 (1994); Kim, et al., Polyurethanes having shapememory effect, Polymer 37(26):5781-93 (1996); Li et al., Crystallinityand morphology of segmented polyurethanes with different soft-segmentlength, J. Applied Polymer 62:631-38 (1996); Takahashi et al., Structureand properties of shape-memory polyurethane block copolymers, J. AppliedPolymer Science 60:1061-69 (1996); Tobushi H., et al., Thermomechanicalproperties of shape memory polymers of polyurethane series and theirapplications, J. Physique IV (Colloque C1) 6:377-84 (1996)) (all of thecited literature incorporated herein by this reference).

The scope of the invention extends to the use of SMP foams for use inelastic composite structures, wherein the capsular shaping elementutilizes the polymer foam together with an expanse of nickel titaniumalloy. See Watt A. M., et al., Thermomechanical Properties of a ShapeMemory Polymer Foam, available from Jet Propulsion Laboratories, 4800Oak Grove Drive, Pasadena, Calif. 91109 (incorporated herein byreference). SMP foams function in a similar manner as the shape memorypolymers described above. The scope of the invention also extends to theuse of shape memory polymers that are sometimes called two-way shapememory polymers that can moved between two predetermined memory shapesin response to varied stimuli, as described in U.S. Pat. No. 6,388,043to Langer et al. (incorporated herein by reference).

Other derivatives of SMPs within the scope of the invention fall intothe class of bioerodible shape memory polymers that again may be used incertain elastic composite capsular shaping structures. As will bedescribed below, one embodiment of capsular shaping element may bedesigned with composite portions that define a first modulus ofelasticity for a period of time after implantation to resist force thatmay be applied by fibrosis during wound healing, followed by a secondmodulus of elasticity following biodegradation of a surface portion ofthe elastic composite structure.

In all variants of capsular shaping element that make use of expanses ofthin films or composites of shape memory materials, the principalobjectives relate to the design of an implant that will impart to theimplant/lens capsule complex an unstressed more spherical shape with alesser equatorial diameter when zonular tension is relaxed, and astressed flatter shape with a greater equatorial diameter in response tozonular tensioning forces. The superelastic component will provide theability to absorb known amounts of stress—and release the energy in apredetermined manner in millions of cycles over the lifetime of theimplant in cooperation with an optic that will provide variable focus.

Exemplary Biomimetic Intracapsular Devices with Superelastic or ElasticComposite Components

A. Type “A” Implantable Intraocular Devices. FIG. 4 illustrates acut-away view of an ultrathin flexible, deformable intraocular device(IOD) in the form of a capsular shaping element 100 corresponding to thepresent invention implanted in a capsular sac or bag 102. FIG. 5illustrates a hypothetical capsular sac 102 that defines an anteriorcapsule 104A and a posterior capsule 104B after removal of thecrystalline lens matrix LM. This disclosure will adopt the terminologycommonly used by ophthalmologists that defines the anterior capsule asthe portion of the capsular sac anterior to the capsular equator 108,and the posterior capsule as the sac portion posterior to the equatorialregion. In FIG. 5, it can be seen that an anterior engagement plane Aand a posterior engagement plane B comprise annular (inner) portions ofthe anterior and posterior capsules 104A and 104B that are substantiallyengaged by the capsular shaping element 100 of FIG. 4. The anteriorplane A and posterior plane B are radially outward of a central opticzone indicated at C that ranges from about 4.5 to 7.0 mm in diameter.The anterior and posterior planes A and B are radially inward of anequatorial region indicated at E. In this disclosure, the term axis andits reference numeral 115 are applied to both the natural lens capsuleand the capsular shaping element 100, and the term axis generallydescribes the optical axis of the vision system. The axial dimension ADrefers to the dimension of the capsular implant or implant/lens capsulecomplex along axis 115.

In FIG. 4, the capsular shaping element 100 comprises a thin-filmexpanse 120 of a shape memory material, in this case a nickel titaniumalloy, that is encased in a thin layer or coating of a biocompatiblepolymer 122. FIG. 4 thus shows the capsular shaping element 100 in aperspective view as it would appear in an unstressed state—similar toits appearance prior to its implantation—and maintaining the lenscapsule in an open more spherical shape. The combination of the capsularshaping element 100 and the natural lens capsule, defined herein as theimplant/lens capsule complex, is adapted to provide a biomimetic lenscapsule that can cooperate with the eye's natural accommodationmechanisms to enable a new class of accommodating lens systems thatmimic a naturally accommodative human lens capsule.

The IOD 100 of FIG. 4 defines a first anterior surface portion 105A thatis adapted to engage the anterior plane A of the anterior capsule 104Aof FIG. 5. The capsular shaping element 100 further defines a secondposterior surface portion 105B that is adapted to engage the posteriorplane B of the posterior capsule 104B of FIG. 5. The capsular shapingelement 100 of FIG. 4 illustrates a device that has a discrete number ofspaced apart peripheral arcuate extending body portions 112 a-112 n(where n indicates an integer) that are formed to extend from theanterior plane A of anterior capsule 104A to posterior plane B ofposterior capsule 104B in a meridonal manner relative to axis 115. InFIG. 4, the peripheral extending portions 112 a-112 n transition to ananterior annular body portion indicated at 124 a. As will be describedin another embodiment below, the annular body portion 124 a can bepositioned anteriorly or posteriorly in the capsular sac. In theembodiment of FIG. 4, the posterior surface portion 105B comprises aplurality of regions of each arcuate peripheral body portion 112 a-112n. It should be appreciated that the number of spaced apart arcuateperipheral portions 112 a-112 n can range from about 2 to 20, andmoreover the wall portion 127 of the capsular shaping element 100further can extend about the entire circumference of the IOD so thatthere would not be a plurality of discrete elements, particularly whenan elastic composite is used as will be described below.

FIG. 6 shows an alternative embodiment wherein the capsular shapingstructure 100 has other optional features and characteristics. First,the thin-film shape memory expanse 120 is insert-molded with a foldableposterior annular polymer portion 124 b to thereby provide a broaderposterior surface portion 105B to engage plane B of the capsular sac.Further, the intracapsular implant defines an at least partly annularabrupt edge portion 126 (collectively) or projecting ridge for engagingthe capsule interior to limit cell migration within the interfacebetween the lens capsule and the implant. Preferably, such an annularedge 126 is provided both on the anterior and posterior surfaces of theimplant 100. Third, the thin film shape-memory expanse 120 is shown withmicro-machined fenestrations 128 which can be utilized to controllocalized stress-bearing capacities of the shape memory material. Bothshaping elements 100 of FIGS. 4 and 6 can be rolled for introductioninto the patient's eye.

Of particular interest, the capsular shaping element 100 of FIGS. 4 and6 carries a thin film shape-memory alloy form 120 having a thickness ofbetween about 5 microns and 50 microns. More preferably, the singlelayer of SMA 120 has a thickness between about 10 microns and 40microns. The nickel titanium alloy form also is fabricated to define anA_(f) (austhenite finish temperature) at less than about 37° C. Toprovide the thin film with the selected A_(f), the element is composedof between 45-55% each of titanium and nickel. As described above, thecapsular shaping element 100 then will function is it superelasticcondition to cooperate with the force of contraction of the humanciliary muscle and zonular tensioning (about 1 to 3 grams of force)about the equator of the capsular sac. In other words, the contractingforces of the ciliary muscle will be sufficient to deform theintraocular device 100 to provide the lens capsule complex with a lesseraxial dimension—i.e., a flatter shape. Upon relaxation of the ciliarymuscle and zonular tensioning about the equator of the capsular sac, theintraocular device 100 defines recoverable strain properties thatreturns the element to a less stressed state wherein the intraoculardevice has a greater axial dimension—i.e., a more spherical or globularshape.

The capsular shaping element 100 of FIGS. 4 and 6 corresponding to theinvention also can be defined by its selected dimensions and its 3-Dshape for engaging and supporting the interior of the capsular sac. Theouter envelope dimensions of an accommodative lens capsule are about 3.0to 5.5 mm. about the optical axis, with a diameter ranging from about8.0 to 10.0 mm. Thus, the outer envelope of the capsular shaping element100 as defined by its planform and molded memory shape (its unstressedstate) would match the three dimensional shape of a youngstill-accommodative lens capsule. The thin-film SMA form together withthe capsular sac (i.e., the implant/capsule complex) defines an axialdimension AD greater than about 3 mm. when not subject to zonulartensioning forces. Further, the thin-film expanse that comprises thecapsular shaping element 100 has a selected thickness and planform thatdemonstrates stress/strain recovery at 37° C. in response to zonulartensioning forces that flattens the axial dimension AD to less than 3.0mm. and preferably lessens the dimension AD by about 1.0 mm. to 2.5 mm.Upon release of zonular tensioning forces, the superelastic thin filmexpanse 120 will rapidly return the implant/capsule complex to itsunstressed state and shape.

The capsular shaping element 100 (FIG. 4) further has a thickness andplanform that demonstrates stress/strain recovery at 37° C. in responseto zonular tensioning forces that allows stretching of the equatorialdiameter of the implant/capsule complex by greater than about 10%. Morepreferably, the shape memory implant demonstrates stress/strain recoveryat 37° C. in response to zonular tensioning forces that allowsequatorial stretching by greater than about 15%.

The ciliary muscles CM, choroid and zonular fibers each have a modulusof elasticity, and the capsular shaping element 100 in combination withthe capsular sac (i.e., implant/capsule complex) defines a lower modulusof elasticity than any of these tissues to insure they do notunnaturally deform during accommodation. A capsular shaping element 100that carries a nickel titanium alloy form, in its superelastic statewhen at body temperature, is the optimal material for deforming inresponse to zonular tension by absorbing stress and thereafter releasingthe absorbed energy to return the complex of the shaping element andlens capsule to its memory shape. In one embodiment corresponding to theinvention, the intraocular device carries a seamless thin-film shapememory form that demonstrates a stress/strain recovery greater than 3%at 37° C. More preferably, the thin-film shape memory form demonstratesa stress/strain recovery greater than 5% at 37° C.

FIG. 7 illustrates, for convenience, a single peripheral arcuate bodyportion 112 a of an alternative embodiment of capsular shaping structure140 and engagement planes A and B. All such peripheral body portions ofthe shaping element would have a similar shape and function as thesingle element of FIG. 7. In this variant, the element 140 has anadditional “S” curve or bend portion 144 in the shape memory alloy thatserves two purposes. First, the additional curve 144 together with thetwo radially outward curves 145 a and 145 b can develop greater elasticenergy-absorbing and energy-releasing forces than the correspondingelement 100 of FIG. 4. The embodiment in FIG. 7 places the superelasticstructure more directly between planes A and B. This embodiment 140provides greater strength that the lesser hoop strength of the device ofFIGS. 4 and 6 wherein a single bend portion 145 is provided in thedevice that urges apart planes A and B.

The second advantage offered by the device 140 of FIG. 7 is that it willsubstantially engage the lens capsule 102 except for an equatorial bandof the capsular sac. As can be seen in FIG. 7, the diameter 146 of thenatural lens capsule is shown as it would be engaged and supported bythe CSE as in FIG. 4 to provide a substantially elliptical or singleradius equatorial region. As can be seen in FIGS. 7, 8A and 8B, theshaping element 140 of FIG. 7 defines a radially outward equatorialenvelope that is substantially non-elliptical and without a radius thatdirectly blends into the curvature of the anterior and posteriorcapsules. Thus, the shaping element 140 of FIG. 7 has a lesser maximumdiameter 148 as indicated in FIGS. 8A-8B that will support the capsularsac in a lesser maximum diameter. It is believed that the shapingelement 140 will thus support the capsular sac in an optimal openposition—but allow the equatorial region of the capsule to shrinkcontrollably after the evacuation of the crystalline lens matrix asoccurs in the wound healing response and fibrotic response. This slightshrinkage of the capsular equator will then take any slack out of thezonular ligaments ZL which are believed to become lax due to lens growthover the lifetime of the patient. This will allow for more effectivetransfer of forces from the ciliary muscle CM to the shaping element 140via the tightened equatorial region of the capsular sac 102.

FIG. 9 illustrates a portion of an alternative embodiment of capsularshaping device 150 corresponding to the invention that again is adaptedto engage planes A and B (see FIG. 5) of a capsular sac 102. Thisembodiment differs in that the peripheral arcuate portions, or theentire expanse, comprise an elastic composite material (ECM) 152 thatcarries first and second thin-film NiTi expanses slightly spaced apartand molded into a substantially thick polymer portion indicated at 155.The first SMA form 158 a is similar to previous embodiments and thesecond layer of thin-film nickel titanium alloy is indicated at 158 b inFIG. 9. By assembling this composite structure, the implant can provideenhanced load-bearing and response capacities that, for example, may notbe attained by a single thin-film NiTi form within an implant body.

FIG. 10 illustrates an exemplary part of an alternative embodiment ofcapsular shaping element 160 that is similar to previous variants thatengage planes A and B (see FIG. 5) of a capsular sac 102. Thisembodiment differs in that the equatorial portion 162 of the shapingelement that flexes in response to stresses applied by the ciliarymuscle carries a biodegradable shape memory polymer 165 (or anybiodegradable polymer known in the art). A preferred biodegradablepolymer is a PHA (polyhydroxyalkanoate), or a co-polymer of a shapememory polymer and a PHA. The purpose of the biodegradable polymerportion 165 is to selectively alter the stress (load) bearing capacityof the equatorial portion 162 of the shaping element over time. It isbelieved that the initial wound healing response in the capsular sacfollowing removal of the lens matrix will apply shrinkage or fibroticforces that will lessen after the wound healing response is over. Forthis reason, the inventive capsular shaping element 160 can have a firstgreater load-bearing capacity for selected one week to month periodafter implantation. The capsular shaping element 160 then can define alesser stress-bearing capacity after the biodegradable polymer 165 hasdegraded—with the lesser stress-bearing capacity being optimized forcooperating with tensioning forces applied by the ciliary musclefollowing wound healing.

FIG. 11 illustrates a portion of another alternative embodiment ofcapsular shaping element 180 that functions generally as the previousvariants that engage planes A and B of a capsular sac 102. Thisembodiment differs in that the equatorial portion 182 of the shapingelement that flexes in response to stresses applied by the ciliarymuscle during accommodation carries an adjustable shape memory polymer185. For example, the polymer can be a shape memory polymer thatresponds to stimuli from an external source to alter its modulus orshape between first and second memory shapes to selectively alter thestress (load) bearing capacity of the equatorial portion 182 of theshaping element at any time following its implantation. As describedabove, a shape memory polymer can be designed for photothermalmodification at a selected level above body temperature to adjustmodulus, flexibility, or permeability.

This aspect of the invention is shown in FIG. 11 wherein the externalstimulus is light energy (e.g., a wavelength between 380 nm and 1800 nm,not limiting) that can alter the temperature or other parameter of thepolymer to change its modulus or shape—which will alter thestress-bearing parameters of the composite. In the embodiment of FIG.11, the adjustable shape memory polymer 185 is depicted as an exteriorlayer of the element 180 so that it is more easily exposed to a lightbeam 188. The light beam can be scanned and with an eye tracking systemas is known in the art. The scope of the invention thus includes the useof an external energy source to modify the modulus, flexibility,permeability or other operational parameter of a non-optic portion of anintracapsular implant to optimize its resilient characteristics forenhancing the functionality of an accommodating lens system. It isbelieved that post-implant adjustability of such parameters will becritical for optimization of such accommodating lens systems. Themodifiable polymer can be located in an region of the ophthalmicimplant. The scope of the invention includes any form of stimulus, suchas energy from a light source, electrical source or magnetic source.

FIG. 12 illustrates another embodiment of capsular shaping element 200that is similar to the implant of FIG. 4. This version differs in thatthe polymer portion is shown as extending substantially in a completeexpanse 210 that conforms to the inner surface of the capsular sac.Preferably, the expanse 210 is of a transparent material, and in oneembodiment is any biocompatible urethane, silicon-urethane copolymer oranother shape memory polymer described above. In this embodiment, thethin-film nickel titanium alloy 220 is insert molded into the polymerbody portion to provide the stress-bearing capacity of the shapingelement.

In all of the above described embodiments, the capsular shaping elementand the remaining capsule sac is adapted to mimic a natural lens capsulein balancing its energy-absorbing and energy-releasing characteristicswith the forces applied by the ciliary muscle. The capsular shapingelement will thus prevent atrophy of the ciliary muscle and allow it tocooperate with, and adjust, the next optional component of the inventionwhich is a cooperating independent IOL or an integrated optic element.

Still, it should be appreciated that the capsular shaping devices ofFIGS. 4 to 11 comprise an important ophthalmic implant innovation. Thecapsular shaping devices will maintain the capsule as an open and viablestructure, thus allowing the ophthalmologist to insert and replace anyIOL as required to adjust the lens power over the lifetime of thepatient. Explanting an in-the-sac IOL is not simple with current IOLssince the designs are intended to be shrink-wrapped in the capsule tomaintain lens centration. In the future, it is likely that ultra-thinSMA haptics with thin optics will allow the development of replaceableIOLs that can be inserted and removed with a sub-1.0 mm. entry throughthe cornea making the IOL exchange an atraumatic procedure. It isbelieved that IOL replaceability will become a needed refractive optionin clear lensectomy procedures to treat presbyopia, wherein over thelifetime of the patient a refractive lens change may be required due torefractive drift, or lens exchange for a new lens technology may bedesired (e.g., for a wavefront corrected lens).

B. Type “B” Implantable Intraocular Devices. The Type “B” intraoculardevices generally combine any of the Type “A” capsular shapingstructures of the invention with an integrated optic portion to therebyprovide an integrated accommodating IOL system. FIGS. 13A-13B and 14illustrate a various views of a capsular shaping body 400 with shapememory alloy form 120 therein similar to that of FIG. 4 with anintegrated optic element 410 coupled to the shaping element 400 byhaptic portion 412. The haptic portions 412 (i) can be fixedly coupledto body 400, (ii) can be adapted to resiliently press outwardly toself-locate about the equator of the body 400, or (iii) can be adaptedto cooperate with an engagement element in body 400 as shown in FIG. 19.FIGS. 13A-13B illustrate how changes in the shape of the CSE portion 400are captured to cause the optic element 410 translate anteriorly lens toprovide additional focusing power. Thus, the IOL system of FIG. 14provides a substantially true accommodating lens system based on themechanism of lens translation. In use, pseudo-accommodative vitreousdisplacement also would be enhanced by the implant that presents asubstantially large convex body surface toward the vitreous, which wouldbe an improvement over the reduced surface area of a shrink-wrappedposterior capsule. In this embodiment, the haptic portion 412 again is asuperelastic NiTi form encased in a polymer that is further molded totransition to a central foldable lens as in known in the art.

FIGS. 15A-15B illustrate views of an alternative embodiment ofintegrated IOL 500A with a capsular shaping element portion 505 havingNiTi form 120 therein together with an integrated optic portion 510coupled to the shaping element 505 by an intermediate fixed couplingportion indicated at 502. In this embodiment, the optic portion 510 is aflexible fluid-filled optic with an anterior deformable surface layer504A and an optional posterior deformable surface layer 504B thatcontains a displaceable fluid or gel media M therebetween. In such anadaptive optic embodiment, each surface 504A and 504B can comprise alens element with the displaceable media having any index, or thesurfaces 504A and 504B can contain an index-matched displaceable media Mtherebetween to effectively function as a single optic element. As canbe seen in FIGS. 15A-15B, the change in shape of the capsular shapingportion 505 will alter the curvature of a deformable lens surface, orboth surfaces, ac and pc to ac′ and pc′ while translating the opticanteriorly and increasing the thickness of the lens—all of which mimic anaturally accommodating lens to provide lens accommodation. FIG. 15Cshows an alternative integrated IOL system 500B wherein the peripheralcapsular shaping body 505 is as described previously with a SMA formtherein to provide the capsular sac with the desired strain-absorbingproperties. In this embodiment, the central optic portion 510 again is aflexible fluid-filled optic but with foldable (but non-adaptive)anterior and posterior lens elements 540 a and 540 b that contain adisplaceable fluid or gel media M therebetween, either index matched ornon-index matched. In the embodiment of FIG. 15C, the anterior andposterior lens elements 540 a and 540 b move apart during accommodationto increase lens power. In essence, this system emulates a natural lenscapsule.

FIGS. 16A-16B are views of a Type “B” implant device 500C that has acapsular shaping body portion 505 together with a refined microfluidicsystem for causing fluid flows into a deformable adaptive optic portion510 from a peripheral non-optic portion 512 that is adapted to engagethe capsular sac. As can be seen in FIG. 16B, the capsular shaping body505 has a plurality of peripheral arcuate extending elements 516 a-516 dthat can number from about 3 to 12. Alternatively, the body portion 505can extend 360° about the implant, or a plurality of elements with anintermediate thin sheath element can extend 360° about the implant. Theimplant defines an open anterior central region.

In the implant 500C of FIGS. 16A-16B, the peripheral capsular shapingportion 512 carries several features that can assist in causing a lenselement or elements provide accommodative effects. The peripheral bodyportion 512 transitions to an annular body portion 526 that carries aposterior lens 520 with a deformable anterior surface 525 that can becontrollably deformed by the flow of an index-matched fluid media M toand from an interior space or chamber indicated at 522B. The lens isdeformed by flow from at least one peripheral chamber 522A in theperipheral elements 516 a-516 d. The fluid flows are designed to occurwhen elements 516 a-516 d are deformed from their memory shape (FIGS.16A and 20A) to a temporary shape (FIG. 20B) by zonular tensioning. Thememory shape of the body 505 again is provided by a superelastic NiTiform embedded therein (not shown). The peripheral body portion 512, asin all earlier embodiments, is adapted to deform under about 1.0 to 3.0grams of applied force about the equatorial region of the implant.

In one embodiment as depicted in FIG. 16A, the lens 520 has a negativepower and is adapted to cooperate with an independent positive powerlens that is implanted in the open central portion of the capsularshaping body 505 as shown in phantom view in FIG. 19. It should beappreciated that the system of the invention can be designed for fluidflows to or from the central optic to add or subtract power to apositive power lens, a negative power lens or a plano lens.

FIG. 17 is a view of the intraocular device of FIGS. 16A-16B showing amethod of rolling the device for introduction into the eye, wherein thebody 505 is an assembly of a superelastic SMA form insert molded into ashape memory polymer, and the SMP then is compacted to a temporaryshape. In such a preferred embodiment, a thin film NiTi form or a NiTiwire form together with the polymer component would be very thin. Theperipheral body portion would be in the range of 25 to 100 microns inthickness, which is suitable for rolling or folding as shown in FIG. 17.

FIG. 18 is an exploded view of a manner of fabricating the implant 500Cof FIGS. 16A-16B showing two components 532 a and 532 b de-mated withmolded-in flow channels 540 that would communicate between the interiorchambers of the optic portion and peripheral non-optic portion. In thisembodiment, the deformable lens layer 525 is substantially thin whilebase potion 524 of the lens is less deformable or preferablynon-deformable. The superelastic SMA form 120 (see FIG. 4) is moldedinto either or both polymer components 532 a and 532 b. A fluid media Mis inserted into the chambers during or after bonding together thepolymer components 532 a and 532 b.

FIG. 19 is a sectional view of an intraocular device 500C similar tothat of FIG. 16A showing that the body 505 carries an engagementstructure indicated at 560 for cooperating with and positioning theengagement ends 564 of haptics 565 that carries lens 580 (phantom view).FIG. 19 further shows how the optic 580 would translate to provide anaccommodative effect as in the previous embodiment of FIGS. 13A-13B and14.

Now turning to FIGS. 20A-20B, the movement of the peripheral capsularshaping body 512 from its memory shape to a temporary shape will causecompression of wall portion 528 a against wall portion 528 b to displacefluid media M from interior chambers 522A (collectively) to the interiorspace 522B in the lens 520 to alter it curvature to AC′ from AC. Thescope of the invention includes any of a variety of mechanisms andcavity shapes in the non-optic portion 512 that are compressed to causefluid media flow to the optic portion. Also, the scope of the inventionincludes mechanisms and cavity shapes in the non-optic portion 512 thatare expanded to cause fluid media flow from the optic portion. Theinterior space in the lens can be (i) centrally located or (ii)peripherally located in an annular region to thereby allow thedeformation of the surface to add or subtract power in a plano lens,positive power lens or negative power lens. The peripheral extendingportions 516 a-516 d carry NiTi forms either of a thin film expanse orwire forms to induce the portions 516 a-516 d toward the memory shape aswell as return the chambers 522A to a “memory” volume. The sectionalview of FIG. 16A illustrates the capsular sac and implant at, or urgedtoward, its memory shape as when implanted in a lens capsule LC(reference letter LC indicating the interior of the lens capsule). Itcan be seen that a substantial volume (first volume) of fluid media M iswithin the peripheral non-optic portion and chambers 522A therein. Inthis untensioned or memory state, there is a limited volume of media Min the interior space 522B of the lens.

In a disaccommodative state, referring to FIG. 20B, the sectional viewshows the body portion 512 in a tensioned collapsed (temporary) shapewhen zonular tension flattens the lens capsule and collapses the axialdimension of the implant along optical axis 515. It can be seen that theaxial collapse of implant causes compression of the peripheral chambers522A and moves a volume of fluid media M into space 522B of the lens520. The increased fluid pressure in the space 522B thereby deforms thelens surface 525 and subtracts from the negative power of the lens. Itcan be easily understood how this added fluid pressure can be used toreshape a lens to make a deformable surface, whether (i) to make thecurvature steeper or flatter with a central interior space 522B or anannular interior space 522B; (ii) to add power or subtract power; or(iii) to move a piano element away from non-refractive parameters towardeither a positive or negative power. It is important to note that themethod of the invention includes providing a large fluid volume in theperipheral chambers 522A when compared to the lens chamber 522B tothereby provide hydraulic amplification means for transducing andamplifying the mechanical flexing of the body portion 512 to maximizelens deformation. FIG. 21 is a sectional view of an alternative adaptiveoptic device 500D wherein flexure of the peripheral portion 512 to aflatter shape impinges on the volume of the peripheral chamber portions522A to subtract from the power of a bi-convex lens by adding anindex-matched fluid media to the chamber portion 522B within the lens520. It can be seen that the deformable surface 525 is restrained at theannular optic periphery by webs 580 to control the shape change inresponse to fluid media flow.

In any design of capsular shaping body or for an accommodating lenssystem, it may be necessary to provide post-fabrication adjustment meansfor (i) adjusting the flexibility and response to the peripheral body'sdeformation after implantation, (ii) the exact shape of a dimension ofthe implant to engage the lens capsule, (iii) the amplitude ofaccommodation, as well as (iv) providing for adjustment of lens opticparameters. To provide for such adjustments, FIG. 22 shows a cut-awayview of a capsular shaping body and lens similar to the embodiment ofFIG. 16A. A plurality of regions 588 of the capsular shaping body are ofa shape memory polymer that is disposed adjacent to an interior space orchamber in the implant. Each SMP portion is responsive to an externalenergy source that cause it to swell to thereby impinge on the chamberto reduce its volume (increase internal fluid pressure). While theregions are discrete and spaced apart in FIG. 22, they also may beannular or comprise a thin layer of a polymer expanse. Similarly, theSMP regions (not shown) may extend within broad surface regions of thecapsular shaping body to alter its modulus or flex characteristics. Inparticular, altering the mechanical properties of the polymer bodycomponent can offset and cooperate with the properties of the NiTi form120 therein to alter the resilient characteristics of the composite.

FIGS. 23-24 illustrate a capsular shaping system with a first shapingbody 500C similar to that of FIG. 16A together with a second independentinverted shaping device 600. The first device is adapted to engage theposterior capsule and a limited equatorial region (cf. FIG. 16A). Thesecond device 600 is adapted for engaging only the anterior capsule anda limited equatorial region. The second shaping device 600 has a numberof extending portions 616 a-616 d that cooperate with and are spacedbetween the corresponding portions of the first device 500B whenimplanted in a capsular sac. The second device 600 further defines anannular portion 605 that transitions into the extending portions 616a-616 d. Of particular interest, the use of first and second independentshaping devices for engaging the anterior and posterior capsules withindependently responsive elements allows the lens capsule to respond tozonular tensioning and de-tensioning more like a natural lens capsule.This can be understood by reference to equatorial indicator markings onthe implants in FIGS. 23 and 24 which show the device in accommodativeand non-accommodative shapes, respectively. It can be seen that theaxial dimension of the capsular complex moves from AD to AD′ as thesystem moves toward a disaccommodative shape (FIG. 24). It can easily beunderstood (see arrows) that movement of the capsule complex toward itsnon-accommodative equatorial dimension will cause the extending portions516 a-516 d and extending portions 616 a-616 d to adjust or sliprelative to the equatorial plane of the complex. In FIGS. 23 and 24,equatorial indicator markings X and Y on the respective extendingportions 516 a-516 d and extending portions 616 a-616 d are shown indifferent alignments with one another when the lens capsule adjustsbetween accommodative and non-accommodative shapes. Of particularinterest, the independent cooperating capsular shaping bodies willprevent the implant from simply forming a hinge at the equatorial apexof the device. By utilizing such a design feature, a greater amplitudeof capsular shape change can be achieved for a given amplitude ofzonular tensioning. It should be appreciated that the independentdevices 500B and 600 can be coupled by thin flexible membranes (notshown) and fall within the scope of the invention, wherein the posteriorand anterior shaping bodies still substantially provide the desirablefunctionality described above to prevent the hinge effect at theequatorial apex of the device.

The previous embodiments have illustrated peripheral body portions thatare substantially thin and provided with an elastic response due to thesuperelastic SMA form 120 insert-molded therein. Embodiments of adaptiveoptic lens systems as described above are possible without, or with lessreliance on, a superelastic shape memory alloy form in the implant. Inorder to provide a polymer peripheral body portion with suitableresilient characteristics for shaping the capsular sac and responding tozonular tensioning forces, a resilient gel-like shape memory polymer 745can be used to define a memory shape that occupies a substantialperipheral portion of the capsular sac as in implant 700A of FIG. 25.Still, the shape memory polymer can be compacted to a temporary shapeand rolled or folded as in FIG. 17. The fluid media M within theperipheral chamber(s) 722A and optic chamber 722B is non-compressibleand accounts for the bulk of the implant that is introduced by aninjector through the cornea into the capsular sac. FIG. 25 illustratesan implant device 700A that has a posterior lens that is adaptive inpower by exchange of fluid media M between peripheral chamber 722A inperipheral portion 724 and central chamber 722B of lens 720 via channels740. It can easily be seen from FIG. 25 that fluid can be selectivelydisplaced from the periphery to the center when the respective volumesof the peripheral and central chamber portions are altered upon zonulartensioning and de-tensioning. The embodiment of FIG. 25 operates as thedevice of FIGS. 16A-16B with induced fluid flows adapted to deform thesurface 725 of the adaptive lens 720.

FIGS. 26, 27 and 28 illustrate similar embodiments 700B, 700C and 700Dthat have peripheral chamber(s) 722A in various locations within theperipheral body for different strategies in collapsing the interiorchamber(s) 722A therein to enable the adaptive optic. It can beunderstood that the interior chambers can be annular or spaced apart, orany combination thereof and be located in various portions of theimplant periphery. The peripheral chambers can be in equatorial,posterior or anterior portions of the body periphery to alter the powerof a single lens or two spaced apart lenses. The fluid flow channels tothe lens are not shown for convenience.

Those skilled in the art will appreciate that the exemplary systems,combinations and descriptions are merely illustrative of the inventionas a whole, and that variations in the dimensions and compositions ofinvention fall within the spirit and scope of the invention. Specificcharacteristics and features of the invention and its method aredescribed in relation to some figures and not in others, and this is forconvenience only. While the principles of the invention have been madeclear in the exemplary descriptions and combinations, it will be obviousto those skilled in the art that modifications may be utilized in thepractice of the invention, and otherwise, which are particularly adaptedto specific environments and operative requirements without departingfrom the principles of the invention. The appended claims are intendedto cover and embrace any and all such modifications, with the limitsonly of the true purview, spirit and scope of the invention.

What is claimed is:
 1. An accommodating intraocular lens, comprising: anoptic portion comprising an anterior element and a posterior elementdefining an optic fluid chamber; a plurality of haptics extendingradially from the optic portion, each of the plurality of hapticscomprising a haptic fluid chamber in fluid communication with the opticfluid chamber, the plurality of haptics each adapted to deform inresponse to capsular bag reshaping, wherein each of the plurality ofhaptics has a maximum height dimension in an anterior-to-posteriordimension that is at least as great as a maximum height dimension of theoptic portion in an anterior-to-posterior dimension; and a fluid adaptedto be moved between the haptic fluid chambers and the optic fluidchamber in response to deformation of the plurality of haptics, whereinthe anterior element and the posterior element are each adapted todeform in response to the fluid movement between the haptic fluidchambers and the optic fluid chamber to change the power of theintraocular lens.
 2. The intraocular lens of claim 1 wherein theposterior element is adapted to deform less than the anterior element inresponse to the fluid movement.
 3. The intraocular lens of claim 1wherein the volume of fluid in the haptic fluid chambers is larger thanthe volume of fluid in the optic fluid chamber.
 4. The intraocular lensof claim 1 wherein the fluid is index-matched with the anterior elementand the posterior element.
 5. The intraocular lens of claim 1 whereinthe optic portion is recessed in the posterior direction relative to theplurality of haptics.
 6. The intraocular lens of claim 1 wherein theanterior element and the posterior element each have a thickness throughan optical axis of the optic portion, and wherein the anterior elementthickness is less than the posterior element thickness.
 7. Anaccommodating intraocular lens, comprising: an optic portion comprisingan anterior element and a posterior element defining an optic fluidchamber, wherein the optic portion has a maximum height dimension in ananterior-to-posterior direction; a peripheral non-optic portionextending radially from the optic portion, the peripheral non-opticportion comprising a peripheral fluid chamber in fluid communicationwith the optic fluid chamber, wherein the peripheral portion has amaximum height dimension in the anterior-to-posterior direction that isat least as great as the optic portion maximum height dimension; and afluid adapted to be moved between the peripheral fluid chamber and theoptic fluid chamber in response to deformation of the peripheralnon-optic portion due to ciliary muscle movement, wherein the anteriorelement and the posterior element are each adapted to deform in responseto movement of the flowable media between the peripheral fluid chamberand the optic fluid chamber to change the power of the intraocular lens.8. The accommodating intraocular lens of claim 7 wherein the posteriorelement is adapted to deform less than the anterior element in responseto the fluid movement.
 9. The intraocular lens of claim 7 wherein thevolume of fluid in the peripheral fluid chamber is larger than thevolume of fluid in the optic fluid chamber.
 10. The intraocular lens ofclaim 7 wherein the fluid is index-matched with the anterior element andthe posterior element.
 11. The intraocular lens of claim 7 wherein theoptic portion is recessed in the posterior direction relative to theperipheral non-optic portion.
 12. The intraocular lens of claim 7wherein the anterior element and the posterior element each have athickness through an optical axis of the optic portion, and wherein theanterior element thickness is less than the posterior element thickness.